Jangmo-o is a new Dragon-type Pokémon in Sun and Moon that can evolve into the pseudo-legendary Dragon-and-Fighting-type Pokémon Hakamo-o, making it a valuable Pokémon for any player, competitively or not.

Steps

Method1

Under the Tree

1

Traverse through Poni Canyon, until you get near the end of it.

2

Find a tree there.

3

Crawl under it, and there is a small chance that a Jangmo-o will appear.

While this method is difficult, one advantage of it is that past the tree is a small pond where you can find TM35.

Method2

Near the Trial Site

1

Look out for a patch of grass. Once you are almost done with Poni Canyon, you will see a small patch of grass near the trial site.

In this patch, you have a 5% chance to find a Jangmo-o.

2

Boost your chances if you can. Your chances can be boosted by having a Pokémon with the move Sweet Scent in your party, or an ability that increases encounters with wild Pokémon.